CAVITATION VACUUM DEVICE
Original Publication Date: 1980-Aug-31
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
Toner contamination of electrostatographic reproducing apparatus outside the developer housing can be reduced by lowering the pressure within the developer housing thereby reducing the amount of toner which escapes from the developer housing. The figure shows a device whicfi takes advantage of the presence of an exhaust fan in the fuser exhaust duct of the machine to reduce the pressure in the developer housing. Adjacent the low pressure side of fan 10 inside the fuser exhaust duct 12 a conduit 18 with a funnel-shaped opening is placed. The other end of conduit 18 is connected to the developer housing 22 where the pressure drop is desired. With the placement of the funnel-shaped opening adjacent the low pressure side of the fan full advantage may be taken of the cavitating effect of the fan blades, and a greater vacuum may be achieved in the developer housing. Thus, according to Bernouli's Law for streamlines with the placement of the funnel adjacent the low pressure side of the fan, air is sucked out of the developer housing at a greater velocity thereby reducing the air pressure in the developer housing.